Art of image formation and apparatus for forming images



J1me 1941- A. N. GOLDSMITH EI'AL 2,244,688

ART OF IMAGE FORMATION AND APPARATUS FOR FORMING IMAGES Filed March 16,1938 5 Sheets-Sheet l \NVENTO R5." pare-a N 62720 5171 off! Harry 2 Man?fa? Mayer I??? kasfrihfl ATTORNEY J n 10, 1941- A. N. GOLDSMITH ETAL2,244,688

ART OF IMAGE FORMATION AND APPARATUS 7 FOR FORMING iMAGES 5 Sheets-Sheet2 Filed March 16, 1938 fl HHHW J F J I :SpcoM Mm Gag/4 June 1941- A. N.GAOLDSMITH ETAL 2,244,688

ART OF IMAGE FORMATION AND APPARATUS FOR FORMING IMAGES Filed March 16,1938 5 Sheets-Sheet 5 ATTORN EY J1me 1941' A. N. GOLDSMITH ETAL2,244,588

ART OF IMAGE FORMATION AND APPARATUS FOR FORMING IMAGES Filed March 16,1938 5 Sheets-Sheet 4 in??? c' ee? 010596 0695814 n 2 lll/ //u/ 2/ 3 2 2am i739 T T C F- 'c' lj 'gfl H 5 c. '4 T 6 H 5 C D R B C D H ll 1 I l ll L If H 2 14. F A on a sco an: R500 R560 1 INVEI l 'l 0 ?5.' fty 5F6396? M Goflsmz zfi r 112 17- l .f'7=71 Pfse June 10, 1941- A. N.GOLDSMITH ETAL 2,244,688

ART OF IMAGE FORMATION AND APPARATUS FOR FORMING IMAGES Filed March 16,1938 5 Sheets-Sheet 5 Ham? 2 Jrcunel Scamqizy q Scunnz'n Ppry'od HRHAT'TORN EY Patented June 10, 1941 UNITED STATES PATENT OFFICE ART OFIMAGE FORMATION AND APPARA- TUS FOR FORMING IMAGES New York ApplicationMarch 16, 1938, Serial No. 196,242

6 Claims.

Our invention relates to the art of image formotion by means of anoptical objective and intermittent photo-illumination of the objectspace of such objective, particularly where the photo-illuminationilluminates one after another regions of an object space spaceddifferent distances from the optical center of the objective along itsoptical axis.

Our invention is particularly applicable to increased range systems inthe art of image formation set forth in an application for LettersPatent of the United States Serial No. 149,078, filed June 19, 1937,wherein regions in the obiect space of an objective lens and at axiallydifferent distances therefrom are illuminated to photographic ortelevision intensity one by one, and the rays emanating from therespective regions, as illuminated and converged by the objective lens,have their convergence points shifted by an assembly of transparentplates of different thicknesses, (or equivalent optical devices). Suchplates having parallel surfaces or forming afocal lenses we havedesignated diflos," and they are moved across the optical axis insynchronous relation with the illumination to photo intensity of therespective regions.

We shall use herein the terms photo-illumination or illumination tophoto-intensity to indicate rays having an intensity and character thatwill form an image, as distinguished from shadows, on suitable media,such as the photochemically sensitive surface of motion picture film,the photo-electrically sensitive mosaic of a television iconoscope, aground glass, or the like, and to differentiate from visual rays capablemerely of stimulating the optic nerve or forming an image on the retina.

Such photo-illumination may be of photographic intensity or oftelevision intensity. To be of photographic intensity the light raysmust be of an intensity and character sufilcient to cfiect the reductionof the salt of the emulsion on the film during an exposure ofone-sixteenth of a second or less. To be of television intensity thelight rays must be of an intensity and character sumcient to form animage on the television pickup device of adequate luminosity to producean electrical output capable of accurate transmission and reproductionof the picture substantially free from objectionable backgroundinterference in the picture due to foreign electrical disturbances inthe circuits, tubes and photo-electric devices. In practice televisionintensity is generally from one to ten or more times the light intensityrequired for photog- 1 raphy on fast emulsions, under similarconditions.

In accordance with the present invention, images are made in cycles eachof which is deemed to consist of (a) a photo period and (b) a photointerval.

The photo period as used herein is to be understood as designating theperiod during which a photo-sensitive surface is subjected to the actionof photo-chemically or photo-electrically effective rays, as, forinstance, the open shutter.

period of a camera having an intermittently moving film, or during theperiod when the image forming rays are deflected but little or not atall from the optical axis by the optical rectifier of a camera having acontinuously moving film,

or the period when the scanning beam is not scanning the object or sceneto be imaged in television, and sometimes called the frame return lineperiod.

The photointerval as used herein is to be understood as defining theperiod when the photosensitive surface is subjected to no, ornegligible, action of photo-chemically or photo-electrically effectiveactinic rays, as, for instance, during the closed shutter period of acamera having an intermittently moving film, the period when the imagerays are bent sharply from the optical axis by the optical rectifier ofa camera having a continuously moving film, and the time other than theperiod designated the frame return-line period when the scanning ray isreturning from the terminus to the start of its path in television.

The term regional flash," as used herein, is to be understood as meaningthe photo illumination respectively identifiable with one of the severalregions of an object space. The complementary action of a regional flashfrom each region is utilized in producing one composite image unit ofthe entire object space.

The term visual illumination, as used herein, is to be understood asdesignating rays which are capable of acting as stimuli to the opticnerves but which are deemed sub-photo rays either because of theircharacter or lack of intensity or their occurrence during a photointerval of a particular photo-sensitive surface.

By our present invention, deleterious effects of regional flashes on theeyes are minimized by providing (a) Groups of regional flashes near thebeginning and near the end of the photo period:

(b) Visual illumination during the photo interval.

The regional flashes at the beginning and end of a photo period mayemanate from the same light source or may emanate from different lightsources, one of which may provide regional illumination from a diflerentangle or intensity or wave characteristic than that provided by theother sources.

The illumination occurring during the photo interval may be of photointensity and character to activate an additional sensitive surface orsurfaces, or may be of an intensity and character to stimulate only theoptic nerves. In the latter case, the visual illumination may be equalin duration to the photo interval, or may be of momentary durationmidway of the photo interval, or may be a series of flashes atintervals, during the photo interval. For instance, a series of flashesof decreasing intensity may be arranged at the beginning of the photointerval.

When the illumination during the photo interval is solely for thepurpose of reducing the deleterious eifect of flicker on the eyes, suchillumination is preferably concentrated in the regions occupied bypersons, and is preferably, although not necessarily, of sub-photointensity. Such concentration can be conveniently effected by means ofproperly timed spot lights having lamps or color filters providing anillumination of the same general color as the photographic illuminationand properly coordinated therewith.

When the illumination during the photo interval of one photo apparatusis of photo intensity, our invention contemplateabut does not require,the utilization of a plurality of cameras so coordi nated in operationthat the photo period of each camera will coincide with the photointerval of the other camera or cameras. If, for instance. two camerasare used, the photo period of one camera will coincide with the photointerval of the other camera, and vice versa. If three cameras are used,the photo period of the first camera may coincide with the last half ofthe photo interval of the second camera and with the first half of thephoto interval of the third camera; the photo period of the secondcamera may coincide with the second half of the photo interval of thethird camera and the first half of the photo interval of the firstcamera; and the photo period of the third camera may coincide with thelast half of the photo interval of the first camera and with the firsthalf of the photo in terval of the second camera.

For special effects. the duration of the photo periods of the severalcameras may be varied relatively to one another and the photo intervalsof the respective cameras proportioned accordingly, even though this mayinvolve some slight overlapping of photo illuminations.

Regardless of the number of cameras, our invention contemplates theprovision of a lighting system complementary to each camera and theillumination by such systems of regions of the set one after another inany desired order. Our invention further contemplates, in its preferredform, the shifting of convergence points of the rays emanating from eachregion, along the optical axis of the camera complementary to thelighting system in action, by the diffo or afocal plates of theparticular camera complementary to the several regions.

The illumination provided by the different lighting systems may differin intensity, concentration, diifusion, angularity and distribution oflight and a given source of light may be connected with a flashing timerof one or more cameras so that the same lamp may be caused to flash atsuch times as corresponds to the proper regional focusing of thedifferent cameras.

By having the photo period of one camera interspersed with the photoperiods of one or more other cameras, the regional flashes requisiteduring the photo period of one camera may be so coordinated with theregional flashes requisite during the photo period of another camera orcameras as to provide flashes of such rapidity and constancy thatvisually perceptible flicker is eliminated and eye strain minimized whenthe flashes are all of photo intensity.

By our invention, the scene on a set may be very rapidly given differentappearances by the rapid variation or alternation of the types ofillumination illuminating the several regions, and severalcinematographic films of a given scene or action illuminated by thedifferent types of illumination may be taken so as to give differentphotographic effects, although the performers are going through but asingle performance or action.

For instance, a black and white motion picture film may be taken by aseries of light flashes of an intensity suitable to the correspondingemulsion, a colored motion picture film may be taken by a series oflight flashes of greater intensity suitable to the sensitivity ofemulsions of the color film, and a stereoscopic picture may be taken bylight flashes of a type and intensity more appropriate for this type ofphotography.

The groups of light flashes used in making the three types of picturesfollow one another so that no one of the films is injured by the seriesof flashes not intended therefor, and the groups of flashes follow oneanother with such rapidity as to eliminate perceptible flicker and hencehave no effect upon the performers or their acting. Several types ofpictures of a given scene or action may be taken from substantially thesame viewpoint, or the cameras may be so arranged that several picturesare taken from different viewpoints, or several pictures of the samegeneral type may be taken from different viewpoints, with lenses ofdifferent focal lengths, angle of view, location, field of view, etc.

By our improvements the performers are relieved from the effects offlicker and are given perfect freedom of action on the set, withconsequent minimizing the acting effort, economy of studio time, andreduction in expense. The production of several different types ofpictures, or pictures made under different lighting conditions. of thesame scene and action permits the editing and coordination of theseveral negatives into a film for projection having a desirable varietyof photographic effects and a maximum of artistic merit and popularappeal.

While our flashing system of illumination for multiple photography underrapidly varying light conditions may be carried out with standard typesof cameras sharply focused on a particular region, its principaladvantages and usefulness are found in conjunction with our method ofimage formation wherein a composite picture of the whole object space ofthe objective lens is made up mosaically by rays emanating from thedifferent regions of the object space at different times and whoseconvergence points are displaced from the plane or planes normallyfunctionally resulting from the focal length of the objective lens andthe respective distances of the several regions therefrom.

Our present invention relates therefore pri-- marily to embodiments ofour increased range systems in which th regions are illuminated byflashing lamps having timed relationships to diflo plates and to theshutter or recti'fler of a camera or the appropriate portion of ascanning cycle of a television pick-up, and a leading object of thepresent invention is to obviate or minimize the deleterious ocularefl'ects of flicker, and to utilize more eil'ectively all or a largeproportion of the flashes produced by forming, upon diflerentphoto-chemical or photo-electrical sensitive surfaces, a variety ofimages of the scene within the object space. Another of the primaryobjects is to enable multiple photography or television pick-upsimultaneously, and with identical or diflerent illuminations therefor.

In the utilization of our improvements in conjunction withcinematographic cameras in which fllm is advanced step by step, theperiodical illuminations to photo intensity must. of course, occur whilethe camera shutter is open to expose the photo-sensitive surface Thisillumination to photo intensity should not be confused withnonphotographic, visual or ocular illumination which may be providedconcurrently with or alternately to the photo illumination to minimizethe tiring of the eyes by flicker.

In accordance with one form of the present invention, the set or objectspace or regions oi the object space are illuminated by the same orcomplementary flashing lamps during the period when the shutter isclosed, as well as during the period when the shutter is open, and theperiods of darkness, unilluminated by flashes, are rendered so brief andnearly equal as to be visually imperceptible.

We have found that the periods of darkness (between flashes ofillumination) should preferably be as nearly equal as possible, and thatthe integrated illuminations therebetween should also be as nearly equalas possible. The flicker produced on a surface intermittentlyilluminated (a) Increases as the brightness of illumination is increasedunder otherwise identical conditions,

(b) Or (to use an approximately equivalent description) increases as thecontrast is increased between the brightness of the illuminated periodsand brightness during the relatively dim periods (which latter may beperiods of total darkness),

Diminishes when the periods of darkness are diminished in length,

(d) Diminishes when the lengths of the periods of darkness are madenearly or altogether alike,

(e) Diminishes when the lengths of the periods of illumination are madenearly or altogether alike, I

(I) And diminishes when the successive intensitles of illumination aremade nearly or altogether alike.

We prefer to describe the flashing and intermittent illumination asbalanced" when conditions d, e and I are fulfllled. Accordingly, wepropose to reduce flicker in such intermittentillumination systems byobserving conditions a, b and c and also balancing" the illumination asdescribed.

When it is desired merely to reduce flicker, in

or shutter openings and the intermittent fllm feeding mechanism that-(a) Two or more groups of lamp flashes are utilized during each periodof rest of the fllm and the groups of flashes are occasioned as near theextremities of the fllm rest period or open shutter period as possible,thereby shortening the time between successive groups of flashes;

(b) The intermittent flashes occurring during the fllm rest period oropen shutter period are completely or partially duplicated during thefllm movement or closed shutter period, to render more nearly uniformthe intervals between the spacing of the intermittent groups of flashes.The flashes occurring during the fllm movement or closed shutter periodsmay be made as dim as is feasible consistently with the desiredreduction of flicker.

(c) During the intervals between the fllm rests or open shutter periods,the portions of the object space occupied by actors who may noticeflicker may be illuminated- I. By a steady light of non-photo intensityand emanating from a colored source or having a color fllter providingrays giving a color generally similar to the color of the flashinglights. Such illumination should be so arranged and directed that theactors will receive visually a suitable amount of light from theseparate illumination during the negative or non-photographic or closedshutter portions of the exposure cycle to prevent the impression offlicker; the minimum intensity of illumination requisite for thispurpose being employed.

2. The separate illumination may be turned on and off in timed relationwith the camera shutter so that no illumination from the separate sourcereaches the set during the active or open shutter portion of theexposure cycle, while the set is being photographed.

The duration of the illumination during the non-photo period of thecycle may be quite widely varied. For instance, a lamp may be turned onat the beginning and turned oil at the end of the non-photo portion ofthe cycle, or may be turned on and oil! repeatedly during the non-photoportion of the cycle, or may be caused to flash repeatedly but withdecreasing intensity during a portion (preferably the early portion) ofthe non-photo period of the cycle. The required or desired groups offlashes may be all produced from a single group of lamps or fromdifferent groups of lamps caused to flash in desired sequence bysuitable timer mechanisms, such as described in application Serial No.149,078, such timers being properly initially coordinated and beingmaintained in coordination by suitable synchronous motors or otherappropriate means.

By suitable coordination of the timer contacts, the rate of flashingduring the photo period of the cycle may be caused to exceed the numberof flashes during the non-photo period of the cycle without giving animpression of flicker, if the flashes occur at a sufliciently rapidrate. For instance, (for each region in the object space) there may beforty-eight flashes per second during the photo periods of the cycle andtwenty-four flashes per second during the nonphoto periods of the cycle.Since the cycle itself ordinarily consumes but one-twenty-fourth s) of asecond or less the intervals between any of the flashes are too smallfor visual perception. Similarly, the intensity of the flashes occurringduring the photo period of the cycle may exceed the intensity of theflashes occurring during the non-photo period of the cycle.

In addition to their elimination of flicker, the flashes occurringduring the non-photo intervals of one camera or image-forming unit mayhe suitably timed and made of sufficient intensity to provide photoillumination for one or more additional photo-chemically orphoto-electrically sensitive surfaces of supplementary image-form ingunits, such as cameras or television pick-ups having a mosaic scanned bya moving electron beam.

In such cases, the timing of the flashes for illuminating the differentregions is so coordi nated with the movements of the diifo plates andphoto intervals of the several units that one set of flashes activatesthe sensitive surface of the film of one unit and another set of flashesactivates the sensitized surface or film of a second unit, and so on foras many different imageforming units as may be desired. The cameras areso interconnected, either mechanically or electrically, as, for example,by synchronized motor operation, that the photo period of one unitoccurs wholly or primarily during the non photo period of the other unitor units. The operation and focus of the two units may be entirelyindependent excepting for the relationship of the timing of the photoperiods to the flashes, and hence one unit may be used to take a close=-up, and another unit may be used to take a medium or long shot, or apicture may be taken from some particular desired angle and with any de-,sired distribution of illumination in the object space in eachinstance. Such distribution may, in practice, be different and suited tothe correct lighting of the corresponding view. Of course, the severalunits may be combined in a single casing to form a composite camera orcombined camera and television mechanism, or each photographic unit maybe separately encased.

It will be noted that by our improvements it is possible to photographsimultaneously a given scene in action from a multiplicity of differentviewpoints and focal lengths, and such effectively simultaneousphotography of a given scene oraction may be taken with diiferent typesof illumination since the flashes illuminating one photo-sensitivesurface are entirely or substantially excluded from the otherphoto-sensitive surfaces and may differ materially from the flasheswhich actuate such other photo-sensitive surfaces.

All of the pictures may be made in sharp focus from front to rear of theset, or portions of the set may be photographed soft" by properlyproportioning optical constants, e. g., the thickness of the diifoplates controlling the illumination from a particular region, as set outin our aforesaid application. Not only may one set of pietures be blackand white, another set be photographed in color, and a third set bestereoscopic pictures, but one set of pictures may be made by nearlyuniform flood lighting giving a low-key picture, while another set maybe made by markedly non-uniform lighting giving contrasting or harsheffects, all as desired. Since the pictures of each set alternate withthe pictures of the other set or sets, they may be interpolated thereinin printing without detriment to the continuity. Further, sound which isrecorded during such multiple photography is in synchronism with eachset of pictures, and thus film cutting and editing is facilitated.

By our increased range system, the freedom of the movements of actors ona set without going out of focus is greatly increased, in fact, there ispractically no limitation on freedom of movement. The simultaneousproduction of multiple aaeaees sets of pictures in identicaltime-coordination with one another and with the action and soundrecording, but taken under different lighting conditions, renders itpossible to modify the composite effect on the screen by suitableselection of pictures from each set in the printing, cutting, orreviewing room.

The characteristic features and advantages of our improvements willfurther appear from the following description and the accompanyingdrawings in illustration thereof.

In the drawings,

Fig. 1 is a diagrammatic top plan view of a set which comprises a numberof regions independently illuminated by sets of flashing lamps suitablydisposed for desired types of lighting in each instance and coordinatedwith a plurality of image-forming units, each having objectives anddiffos comprising sets of afccal plates or plates with parallel surfacesand of different thicknesses through which light from the respectiveregions is transmitted to photo-chemical or -photo-electrical surfacesto form composite pictures of the set which forms the object space ofeach objective;

Fig. 2 is a perspective view illustrating diagrammatically the sequenceof objective, diifo, and photo-sensitive surface utilized when theimage-forming units are photographic cameras;

Fig. 3 is a diagrammatic view illustrating the relationship of theflashes illuminating the several regions to the exposed and unexposedlight sensitive surfaces of the respective units, illustratingdiagrammatically the co-ordination of the flashes with the photo periodsand photo intervals of the photo units;

Fig. 4 illustrates diagrammatically a set having a plurality of regionseach of which may be illuminated in turn by light of differentintensity, wave length, angle, concentration or diffusion, the lightsources being connected in timed relation with photo units viewing theset from different positions at different angles and through objectivesof different focal lengths;

Fig. 5 illustrates diagrammatically the co-ordination of the flashes ofthe different sets of lamps of Fig. i with respective photo units duringthe exposure and non-exposure of the sensitive surfaces of such units;

Fig. 6 illustrates diagrammatically a set having regions each of whichis illuminated in sequence from different light; sources to permit thesequential photographing of all of the regions comprised in the objectspace of each of the photo units having objectives trained on theprincipal center of interest of the set;

Fig. 7 is a diagrammatic view illustrating one method of co-ordinatingthe flashes illuminating the respective regions with the several photounits;

Fig. 8 is a diagrammatic view illustrating a second method ofco-ordinating the light flashes i1- luminating the respective regionswith the several photo units so that the sensitive surface of a unitreceives two distinct activations from each region of its object spaceduring a single exposure of the sensitive surface of such unit;

Figs. 9 to 15 illustrate diagrammatically various suitable arrangementsof flashing to minimize flicker when only a single photo unit is inaction;

Figs. 16 and 17 illustrate diagrammatically the adaptation of ourinvention to a camera having a continuously moving film, and

Figs. 18 to 2G illustrate diagrammatically the ing the mosaic of atelevision iconoscope as the light sensitive surface to which light ispassed from the various regions of a set through an objective and diffo.

As illustrated in Figs. 1 to 3 of the drawings, a studio stage or set Iis provided with a set of sequentially flashing lamps 2, 2, 4 and iwhich may be provided with suitable reflectors (not shown) to confinethe light directed downwardly from the respective lamps substantially tothe foreground region 2, middle foreground region I, middle backgroundregion 2, and background region I of the set, these regions extendingtransversely across the set and following one another in sequence fromthe front to the rear of the set.

The set is provided with a second set of sequentially flashing lamps 2a,2a, la, and 2a having suitable reflectors (not shown) for confining thelight directed downwardly from these lamps substantially to regionsextending diagonally of the set and comprising the diagonal foregroundis, diagonal middle foreground Ia, diagonal middle background to anddiagonal background 9a.

A plurality of concurrently acting lamps, instead of a single lamp, maybe provided for any or all of the regions as illustrated, for instancefor the illumination of the diagonal background region 20.

The flashing lamps may be of known type, as, for instance, lampshavinggas filled bulbs of considerable length through which a highvoltage current is discharged controllably at specified times so as toproduce a number of flashes per second, each fiash being, in general, ofbut a few tens of micro-seconds duration but of high lumen output perfiash. It is generally preferable to use lamps capable of making atleast forty-eight flashes per second and of very high luminous outputper fiash.

The current for illuminating the lamps 2, 2, 4 and i is supplied fromhigh voltage sources such as power-charged condensers III, II, I2 and I!connected with the terminals of the lamps but requiring an inciter ortickler current to initiate the fiash. The timing of the dashing of thelamps 2, 2, l and I is controlled by the supply of inciter or ticklerhigh voltage surges. These surges are transmitted from the secondariesof high tension ignition coils in the transformer assembly it throughthe respective conductors II, II, II and I2 to the respective electrodesis. 22, 2i and 22 contacting with the lamp tubes intermediate the endsthereof. The surges in the secondaries of the coils may be induced bymaking and breaking primary circuits 22, 24, 25 and 22, each containinga battery source and each connected with make and break contacts of atimer 2!. The timer is'operated to make and break the cincuits 22, 24,25 and 26 in desired sequence by a synchronous motor 12 which drives themain shaft 22 of a cinematographic camera 22 for advancing thesensitized film 2| thereof step by step in synchronism with the rotationof the diffo 22 which may supplant the ordinary camera shutter or becoordinated therewith. The diifo 22 has an opaque segment 22 which shutsoff any light from the film 2| during the intermittent movement of suchfilm, and a segment containing the transparent plates 24, 2|, 22 and 21which pass in front of the film gate while a section of the film 2i isstationary in smh gate. The plates 24, 25, 22 and 21 are of differentthicknesses and may have parallel surfaces or may be afocal lenseshaving no image-forming capacity but which are capable of shifting in adirection approximately parallel to themselves and to the optical axisgroups of image rays converged toward the plane of the film 2| by theobjective 22, or may be any substantially equivalent optical system.Tins objective has as its object space all of the set lying within itsfield of view indicated by the lines extending from the objective to thepoints 29 and 42.

The diflo 22 and timer 21 are operated by the synchronous motor 22 sothat the difio plate 24 is in the optical axis of the objective 2! whenthe lamp 2 is flashed. The diifo plate 22 is in the optical axis of theobjective 22 when the lamp 2 is flashed. The diflo plate 26 is in theoptical axis of the objective 22 when the lamp 4 is flashed, and thedifio plate 21 is in the optical axis of the objective 22 when the lamp5 is flashed.

It is obvious that the convergence points of rays emanating from theregions 8, I, I and 9 during the illumination thereof by the flashes ofthe respective lamps 2, 2, l and 5 would ordinarily lie in diflerentplanes after passin through the objective 22, since each such regionwould have its complementary image. plane. But by the interposition ofthe diflo plates the convergence points are shifted by displacing theconverging rays parallel to themselves and to the optical axis of theobjective proportionately to the distances between the image planesnaturally conjugate to the respective regions, the diifo plates havingthicknesses proportionate to the requisite displacements necessary.

1 The current for illuminating the lamps 2a, 2a, 4a and is is similarlysupplied from high voltage sources, such as power-charged condensersIla, Ila, Ho and I2a connected with the terminals of the lamps, theflash of the lamps being initiated by high voltage inciter or ticklercurrent transmitted from the secondary of high tension ignition coils inthe transformer assembly Ila through the respective conductors Iia, lia,I'la and Ila. These conductors have electrodes Isa, 22a, Ma and 22afixed on the ends thereof and contacting with the lamp tubes of thelamps intermediate of the ends of such tubes.

The surges may be induced in the secondaries of the coils in thetransformer assembly Ila by making and breaking primary circuits 22a,24a, 25a and 22a, such circuits including the primaries of the coils, abattery source and make and break contacts of a timer 21a. This timer isoperated to make and break the circuits 22a, 24a, 2la and 26a in desiredsequence by a syn-. chronous motor 22a supplied from the same source ofalternating current as the synchronous motor 22. The synchronous motor280 drives the main shaft 22a of a camera 20a having a difl'o 22aoperated in synchronism with the Geneva movement (not shown) for movingthe film 2Ia step by step. The camera 20a has an objective 22a by whichrays emanating from the regions la, la, la and 2a are focused.

The diifo 22a is provided with diflo pla'tes similar to the difi'oplates of the difl'o 22 and of suitable relative thicknesses to shiftthe convergence points of rays emanating from the respective regions 6a,la, la and 9a parallel to themselves and to the optical axis of theobjective so that the planm of the convergence points of rays emanatingfrom the respective regions are brought into accurate registration withthe light sensitive emulsion on the film 2Ia as the difl'o plates aremoved into the optical axis of the objective one after another.

The contacts of the timer 21a are correlated to the positions oi therespective diifo plates so as to cause a flash of the lamp when thethinnest difl'o plate is in the optical axis, to cause a flash of thelamp 311 when the next thicker difio plate is in the optical axis, tocause a flash of the lamp 4a when the next thicker difl'o plate is inthe optical axis. and to cause a flash of the lamp 5a when the thickestdifio plate is in the optical axis.

The synchronous motors 28 and 28a and their connected parts areinitially so positioned that the flashes produced by the action of thetimer 21 alternate as a group with the flashes produced by the action ofthe timer 21a and the diflo plates of the diffo 32 register with theoptical axis of the objective 38 when the opaque portion of the difl'o32a registers with the optical axis of the objective 38a, and viceversa. The

synchronous motors maintain the initially established relation of theparts. Hence, as indicated diagrammatically in Fig. 3, during the flashproduced by the lamp 2 the diffo plate 34 passes image rays emanatingfrom the region 6 and converged by the objective 38 to the plane of thefilm 3|; during the flash produced by the lamp 3 the difio plate passesimage rays emanating from the region I and converged by the objective 38to the plane of the film 3|; during the flash produced by the lamp 4 thedifi'o plate 35 passes image rays emanating from the region 8 andconverged by the objective 38 to the plane of the film 3|; and duringthe flash produced by the lamp 5 the diffo plate 31 passes image raysemanating from the region 9 and converged by the objective 38 to theplane of the film 3|. During all this period the opaque portion 33a ofthe diffo 32a prevents the passage of any light to the film 3|a and thelamps 2a, 3a, 4a and 5a are not lighted.

After the lamp 5 has flashed, the opaque portion 33 of the diff-o 32shuts off the passage of light to the film 3|. Thereupon, the action ofthe timer 21a causes a flash from the lamp 2a which illuminates thediagonal foreground region 6a and the rays emanating therefrom areconverged by the objective 38a, and are displaced parallel to themselvesby the thin diflo plate so that the plane of their convergence pointcoincides with the sensitive emulsion on the film 3|a. Thereafter, theaction of the timer 21a causes a flash of the lamp 3a which illuminatesthe diagonal middleforeground la and the rays therefrom passing throughthe objective 38a are converged towards image points and in passingthrough the diffo plate are displaced so that the plane of theirconvergence point coincides with the emulsion on the film 3|a.Thereafter the action of the timer 21a causes a flash of the lamp 4a toilluminate the diagonal middle background region 8a, and the raystherefrom passing through the objective 38a are converged towards imagepoints and are displaced by the diifo plate so that the plane of theirconvergence point coincides with the sensitive emulsion on the film 3|a; thereafter the action of the timer 21a causes a flash of the lamps 5ato illuminate the diagonal background region 8a, and the rays therefrompassing through the objective 38a are converged toward image points anddisplaced by the difio plate so that the plane of their convergencepoint coincides with the emulsion on the film 3|a.

It will be understood that the respective lamps provide illumination ofphoto intensity only for the respective regions to which they areappurtenant so that each region is individually and sharply photographedon the film and the photographs of all of the regions of one group orseries are photographed upon a film section from a single frame orpicture unit in the photo period of one camera to form amosaic pictureof the whole set which is in sharp focus throughout. Thereafter, duringthe photo interval of the first camera, the second camera similarlyphotographs on a film section equal to a single frame or picture unit asharp image of each diagonal region one at a time so that during thephoto period of the second camera a mosaic picture of the entire objectspace is made which is sharp throughout.

The photo period of each camera should not exceed one-sixteenth (1 of asecond in duration and ordinarily will not exceed one-twentyfourth (1%)of a second in duration and the multiple flashes during each photoperiod are consequently so rapid as to be visually indistinguishablefrom one another. The photo period of one camera coincides with thephoto interval of the other camera and hence there is a substantiallycontinuous flashing at a rate so rapid as to be substantiallyindistinguishable visually, particularly where the flashes of each groupare balanced and the groups of flashes are balanced.

A conventional photographic sound recorder comprising a microphone I00near the set and connected with a recorder |02 provides for therecording of sound from the set in synchronism with each set of picturesproduced by the cameras 30 and 30A.

In Figs. 4 and 5, we have illustrated diagrammatically a set-up of threecameras 40, 4| and 42. The camera 40 has an appurtenant set of flashinglamps 40a, 40b, 40c and 40d; the camera 4| has an appurtenant set oflamps 4|a, 4|b, 4|c and Md; and the camera 42 has an appurtenant set oflamps 42a, 42b, 42c and 42d. The lamps 40a, Ho and 42a each illuminateto photo intensity the foreground 6, the lamps 40b, 4|b

and 42b each illuminate to photo intensity the middle foreground thelamps 400, He and 420 each illuminate to photo intensity the middlebackground 8, and the lamps 40d, 4|d and 42 each illuminate to photointensity the background 9. The groups of lamps appurtenant to therespective cameras may illuminate the several regions from differentangles to different intensity and with different colors so that eachcamera may not only view the set from a diflerent angle and distance andthrough a lens of different focal length, but also views the set underdifierent lighting conditions.

Each camera, of course, is provided with an objective, diflo,intermittent fllm mechanism, motor, and timer, such as above described.The difio and timer of the camera 48 are so arranged that the respectiveflashes of the lamps appurtenant to this camera occur when the properplates of its diifo are in registration with its objective and while theopaque portions of the diffos of the cameras 4| and 42 are inregistration with their objectives respectively. The difio and timer ofthe camera 4| are so arranged that the respective flashes of itsappurtenant lamps 4|a, 4|b, 4|c and 4|d occur while the appropriateplates of its diifo are respectively in registration with its objectiveand while the opaque portions of the diifo of the cameras 4| and 42 arein registration with their respective objeca,a44,oaa end "closed" andindlcated the flashes of the tives. The diflo and timer of the camera 42are so arranged that the respective flashes of the lamps 42a, 42b, 42cand 42d appurtenant to this camera occur while its appropriate difloplates are in registration with its objective and while the opaqueportions of the diflo plates II and ti are respectively in registrationwith the objectives of these cameras.

In Figs. 6, 7 and 8 we have illustrated diagrammaticaliy an arrangementof four cameras II, ll, 52 and it each focused from a different positionupon a set having a center of interest at the point 54. ,Each of thecameras is provided with an objective, diflo, film mechanism,synchronous motor and timer, such as above described, and hasappurtenant thereto a set of flashing lamps arranged to illuminate oneafter another the respective regions of the object spaces of theobjectives of the respective cameras, the center of interest lying at apoint common to all such object spaces.

The timer, contacts and difl'os of the respective cameras may bearranged as indicated in Fig. 7 in which the flashes of all flve of thelamps Ila, Iilb, 60c, 50d, and tile appurtenant to the camera it occurone after another while the appropriate diflo-plates of the five-platediffo of the camera 50 register sequentially with its objective and theopaque portions of the diflos of the cameras ii, 52 and 53 register withthe respective objectives of these cameras. Similarly each of the fivelamps iiia, Bib, iilc. Sid and ie, appurtenant to the camera 6i, flashone after another while the appropriate diflo plates of this cameraregister one after another with the objective of the camera 5i and theopaque portions of the difio plates of the remaining cameras 50, 52 and53 register with the respective objectives thereof.-

Similarly the five flashing lamps 52a, 52b, 52c, 52d, 2e appurtenant tothe camera 52 flash one after another while the appropriate diflo platesof the camera 52 register one after another with its objective and theopaque portions of the diffo plates of the remaining cameras 56, 5i and53 register with their respective objectives. Similarly the fiveflashing lamps 53a, 53b, 53c, 53d and 53s appurtenant the camera 53flash one after another while the appropriate diffo plates of thiscamera register one after another with its objective and the opaqueportions of the diffo plates of the remaining cameras 50, 5i and 52register with their respective objectives.

If desired, the number of contacts in each timer and the speed thereofmay be increased so that two complete sets of fiashes of each set oflamps occur during the photo period of each camera so that each frame issubjected to a double impression of every region before the film ismoved to bring a new frame into place, as shown in Fig. 8.

It is not of course necessary that each camera should take pictures ofall of the regions in its object space, nor is it necessary that all ofthe cameras should be in action, for the lamps ordinarily appurtenant-tosome of the cameras may be utilized to provide fiashes merely for thepurpose of reducing flicker. Or all the cameras but one may be omittedentirely and any number of timers and lamp equipments appurtenantthereto may be synchronized with one or more cameras in action toproduce a wide variety of sequence of flashes, such as are illustratedin Figs. 9 to 15, inclusive. In these figures we have indicated thephoto period of the camera by the legend open and the photo interval ofthe camera by the leglamps by vertical lines. When but a single camerais in action, it is desirable that only the flashes occurring during thephoto period be of photo intensity. The flashes during the photointerval may be of sub-photo intensity, via, merely visual and may be ofconsiderable duration midway of the photographic interval, asillustrated in Fig. 9; or be flashed midway of the photographicinterval, as indicated in Fig. 10; or may consist of two or more flashesduring the photographic interval as indicated in Figs. 10, ll, 12 and13; or may be segregated at the beginning of the non-photo interval andof decreasing intensity, as indicated in Fig. 14, or may be entirelyomitted during the photo interval and arranged in groups at thebeginning and end of the photo period, as indicated in Fig. 15.

It is not necessary that the film should be moved intermittently as ourinvention is applicable to motion picture cameras having a continuouslymoving film, as for instance, cameras of the type shown in Patent No.2,055,492 and Patent No. 2,056,966. In such cameras the maximum of lightis transmitted to the film when parallel faces of the rectifier 60 areparallel with the continuously moving film 6i passing through the filmgate 62, which is preferably twice the height of a single frame. In suchcase a diffo 63 is interposed between the copying lens 64 and the film,and the regions forming the object space of the camera's objective 65are flashed one after another while the center of the picture istraveling from substantially the point B to substantially the point D orany lesser distance centering on C and physical illumination to preventflicker is flashed while the center of the picture is moving from thepoint C to the point E, or any lesser distance centering on D, asindicated in Fig. 17.

In lieu of converging the image formed by an objective of a camera on asensitized film, as indicated in Figs. 1 to 1'7, inclusive, an image maybe focused by an objective Ill upon the mosaic ll of a televisioniconoscope I2, the image forming rays converged by the objective Illbeing displaced parallel to themselves and to the optical axis by adifio 13 having plates of different thicknesses which respectivelyregister with the objective 10 in synchronism with the flashing oflights illuminating the different regions of the set forming the objectspace of the objective 10. A stream of electrons projected from anelectron gun 14 and controlled by two pairs of deflection plates 15, I6,16' and 11 scans the mosaic of a line at a time, as indicated in Fig.19, and the output of the iconoscope is withdrawn and passes from theconductor 18 into the television transmitter which it controls. Thescanning of the mosaic may be considered as starting at the upper lefthand corner of the picture, as indicated in Fig. 19, and sweeps acrossthe picture one line after another from left to right, the electronstream being blanked out or rendered inactive during the return from theright to the left hand side of the picture. When the scanning stream hasreached the lower right hand edge of the picture, the electron stream isagain blanked out during the period necessary for its return to theupper right hand edge of the picture. This interval between the end ofone scanning operation and the beginning of another scanning operationis kown as the frame return line or blanking period. In accordance withour invention, the regions of an object space of the objective iii arephotoilluminated one after another during the blanking period by flashesof television intensity, as indicated in Fig. 20, so as to provide onthe mosaic ll during this frame return line period a composite andelectrically stored picture of all the regions of the object space oneafter another and all in sharp focus. During the following scanningperiod, the object space, or so much thereof as is occupied byperformers is illuminated by flashes of visual intensity (preferablyphoto-electrically inactive) so as to eliminate the elect of flicker onthe eyes of the performers.

Having described our invention. we claim:

- 1. In the art of dioptric image formation from a scene having objectsin a plurality of regions at different distances from each of aplurality of objectives in the direction of the respective optical axesthereof, the steps which include illuminating the scene tophoto-intensity regionally and one region at a time in regionssubstantially normal to the optical axis of one objective and thenilluminating the scene to photo-intensity regionally and one region at atime in regions substantially normal to the optical axes of theother'objective, dioptrically converging toward an image plane and oneafter another image rays from the group of regions flrst illuminated andthen dioptrically converging toward a second image plane transverse tothe first imge plane andone after another image rays from the group ofregions secondly illuminated, image rays from the first group of regionsforming a composite pictorial image of all the regions of the scene andimage rays from the second group of regions forming a compositepictorial image of all the regions of the scene but from a difierentangle.

2. In the art of dioptric image formation from a scene containing aplurality of objects in the object space of each of a pluraltiy ofobjectives having optical axes intersecting one another within thescene,the steps which include illuminating said scene regionally and oneregion at a time by a plurality of groups of light flashes, said lightflashes together providing photo-periods of similar duration andintensities and photo-intervals of similar duration and at ratesobviating visually perceptible flicker, dioptrically converging towardan image plane normal to one of said optical axes image rays resultingfrom said illumination by one group of flashes, and dioptricallyconverging toward an image plane normal to another of said optical axesimage rays resulting from said illumination by a second group offlashes, the passage of image rays to each of said planes beinginterrupted during the passage of image rays to the other of saidplanes, and varying the normal back focal length of the image raysconverged from one region relatively to the back focal length of theimage rays converged from another region toward each of said planes.

3. The combination with a set, of means for photo-illuminating one afteranother and only one at :a time parallel regions extending across saidset, means for photo-illuminating one after another and only one at atime parallel regions extending diagonally of said set at an angle tothe regions first named, the illuminations of the first named regionsalternating with the illuminations of the second named regions, aphotounit having an objective with an object space ineluding said flrstnamed regions and means for varying the back focal distances of therespective images formed upon the illumination of the respective regionsfirst named, in a predetermined relation to the distances of therespective regions from the objective of the flrst photo-unit, a secondphoto unit having an objective with an object space including saidsecond named regions, means for v rying the back focal distances of therespective images formed upon the illumination of the respective regionssecond named in a predetermined relation to the distances of therespective regions from the objective of the second photo-unit, andmeans for alternately interrupting the passage of illumination from thefirst named means to the image plane of the objective of the secondphoto-unit and for interrupting the passage of illumination from thesecond named illuminating means to the image plane of the objective ofthe first named photo-unit.

4. The combination with a plurality of photo units each including anobjective, each unit also including means for systematically axiallydisplacing images formed by its objecitve, and each unit also includingmeans for supporting a sensitive surface to receive images formed by itsobjective, of groups of light flashers illuminating.

respectively regions spaced along the optical axis of the respectiveobjectives, and means for synchronizing the position of one imagedisplacing means with the flashes of one group and the positon of theother image displacing means with the flashes of the other group, saidflashes illuminating only one of said regions at a time to photointensity the image displacement power of each image displacing means inits severai'positions being functionally related to the distances of therespective regions illuminated by the flashes synchronized therewith andcompensating for the differences in the locations of the regions thatare so illuminated.

5. The combination with a photo unit having an objective, an electrophoto-sensitive surface and scanning means, means for operating saidunit in a cycle providing a photo period and a photo interval, lightflashing means, timing mechanism for flashing said means during saidphoto period and during said photo interval, and a series of transparentplates of different thicknesses movable sequentially between saidsurface and light flashing means in complementary timed relation to theflashes occurring during each photo-period.

6. The combination with a camera having an objective, means for moving afilm continuously and a piano-parallel rotating block through whichimage forming rays from said objective are transmitted to said film, ofa set" in the object space of said objective and means coordinated withthe rotation of said block to provide photo-illumination of the set" insaid object space of said objective while surfaces of said blockaresubstantially parallel with said film and to provide decreasedillumination of said ;set" when an angle of said block is nearest saidALFRED N. GOLDSMITH.

HARRY R. MENEF'EE. WILLIAM MAYER. FRITZ KASTILAN.

